Control of longitudinal dynamics of aircraft using periodic output feedback

In this paper, the problem of pole placement by periodic output feedback is presented. The poles of the discrete time control system could be assigned arbitrarily (with the natural restriction that they should be located symmetrically with respect to the real axis), provided that the number of gain changes is not less than the system´s controllability index. Linearized models of aircraft are obtained at 10 different flight conditions and the controller is designed for controlling the longitudinal dynamics of aircraft using periodic output feedback. The family of 8 plants, representing the longitudinal dynamic, is also simultaneously stabilized. The controller consisted solely of gain elements and did not include a dynamical system, such as an observer, hence it is easier to implement on line.